Room.java

/*
 * (C) Copyright 2014 Kurento (http://kurento.org/)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.kurento.basicroom;

import java.io.Closeable;
import java.util.Collection;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.kurento.client.Continuation;
import org.kurento.client.KurentoClient;
import org.kurento.client.MediaPipeline;
import org.kurento.commons.exception.KurentoException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.socket.WebSocketSession;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonPrimitive;

/**
 * @author Ivan Gracia (izanmail@gmail.com)
 * @author Micael Gallego (micael.gallego@gmail.com)
 * @since 1.0.0
 */
public class Room implements Closeable {
  private final Logger log = LoggerFactory.getLogger(Room.class);

  private final ConcurrentMap<String, RoomParticipant> participants = new ConcurrentHashMap<>();
  private final String name;

  private MediaPipeline pipeline;

  private KurentoClient kurento;

  private volatile boolean closed = false;

  private ExecutorService executor = Executors.newFixedThreadPool(1);

  public Room(String roomName, KurentoClient kurento) {
    this.name = roomName;
    this.kurento = kurento;
    log.debug("ROOM {} has been created", roomName);
  }

  public String getName() {
    return name;
  }

  public RoomParticipant join(String userName, WebSocketSession session) {

    checkClosed();

    if (pipeline == null) {
      log.debug("ROOM {}: Creating MediaPipeline", userName);
      pipeline = kurento.createMediaPipeline();
    }

    log.debug("ROOM {}: adding participant {}", userName, userName);
    final RoomParticipant participant = new RoomParticipant(userName, this, session, this.pipeline);

    sendParticipantNames(participant);

    final JsonObject newParticipantMsg = new JsonObject();
    newParticipantMsg.addProperty("id", "newParticipantArrived");
    newParticipantMsg.addProperty("name", participant.getName());

    log.debug("ROOM {}: notifying other participants {} of new participant {}", name,
        participants.values(), participant.getName());

    for (final RoomParticipant participant1 : participants.values()) {
      participant1.sendMessage(newParticipantMsg);
    }

    participants.put(participant.getName(), participant);

    log.debug("ROOM {}: Notified other participants {} of new participant {}", name,
        participants.values(), participant.getName());

    return participant;
  }

  private void checkClosed() {
    if (closed) {
      throw new KurentoException("The room '" + name + "' is closed");
    }
  }

  public void leave(RoomParticipant user) {

    checkClosed();

    log.debug("PARTICIPANT {}: Leaving room {}", user.getName(), this.name);
    this.removeParticipant(user.getName());
    user.close();
  }

  private void removeParticipant(String name) {

    checkClosed();

    participants.remove(name);

    log.debug("ROOM {}: notifying all users that {} is leaving the room", this.name, name);

    final JsonObject participantLeftJson = new JsonObject();
    participantLeftJson.addProperty("id", "participantLeft");
    participantLeftJson.addProperty("name", name);
    for (final RoomParticipant participant : participants.values()) {
      participant.cancelSendingVideoTo(name);
      participant.sendMessage(participantLeftJson);
    }
  }

  public void sendParticipantNames(RoomParticipant user) {

    checkClosed();

    log.debug("PARTICIPANT {}: sending a list of participants", user.getName());

    final JsonArray participantsArray = new JsonArray();
    for (final RoomParticipant participant : this.getParticipants()) {
      log.debug("PARTICIPANT {}: visiting participant", user.getName(), participant.getName());
      if (!participant.equals(user)) {
        final JsonElement participantName = new JsonPrimitive(participant.getName());
        participantsArray.add(participantName);
      }
    }

    final JsonObject existingParticipantsMsg = new JsonObject();
    existingParticipantsMsg.addProperty("id", "existingParticipants");
    existingParticipantsMsg.add("data", participantsArray);
    log.debug("PARTICIPANT {}: sending a list of {} participants", user.getName(),
        participantsArray.size());
    user.sendMessage(existingParticipantsMsg);
  }

  /**
   * Gets all the participants present in a room.
   * 
   * @return a collection with all the participants in the room
   */
  public Collection<RoomParticipant> getParticipants() {

    checkClosed();

    return participants.values();
  }

  public RoomParticipant getParticipant(String name) {

    checkClosed();

    return participants.get(name);
  }

  @Override
  public void close() {

    if (!closed) {

      executor.shutdown();

      for (final RoomParticipant user : participants.values()) {
        user.close();
      }

      participants.clear();

      if (pipeline != null) {
        pipeline.release(new Continuation<Void>() {

          @Override
          public void onSuccess(Void result) throws Exception {
            log.trace("ROOM {}: Released Pipeline", Room.this.name);
          }

          @Override
          public void onError(Throwable cause) throws Exception {
            log.warn("PARTICIPANT " + Room.this.name + ": Could not release Pipeline", cause);
          }
        });
      }

      log.debug("Room {} closed", this.name);

      this.closed = true;
    } else {
      log.warn("Closing a yet closed room {}", this.name);
    }
  }

  public void execute(Runnable task) {

    checkClosed();

    if (!executor.isShutdown()) {
      try {
        executor.submit(task).get();
      } catch (InterruptedException e) {
        return;
      } catch (ExecutionException e) {
        log.warn("Exception while executing a task in room " + name, e);
      }
    }
  }

  public boolean isClosed() {
    return closed;
  }
}